if your going for close combat always eguit your banshees(if your using them) with the banshee mask, that gives them initiative 10 on the first round of combat and dont forget that they have power weapons
or if your using striking scorpions make sure you equip them with shadowstrike(exarch power) as this allows them to infiltrate,
they have four attacks on the charge, one core, one for double weapons, one for mindiblasters and one for charging.
so definetly use these if your going for combat